Howdy amandathepanda,
Thank your for your patience! That is a great question. So, our HTML before content area is for HTML only, not shortcodes.
However, if you have ever designed even a small WordPress filter before, it would be very easy to create one that will bent that content area to your needs. You would hook into ‘tribe_events_before_html’ and run the content through the WP function do_shortcode, then return it. I believe that will work swimmingly.
Does that make sense? It might sounds like greek if your unfamiliar with the WP API. 🙁 However if you know someone who is WP API savvy, they might be able to help too. Please let me know. Cheers!
– Brook